Just as that figure from Greek mythology spent eternity pushing a rock up a mountain, Castellano’s misfortune was to be stocking the Barbie Zone on the second floor of the Union Square Toys “R” Us on the last business day before Christmas.

Just as he’d get to the top – a fully stocked shelf – another rush of shoppers would send him back down the hill.

“Do you have any Nutcracker Barbies?” customers asked frantically.

“Sold out,” Castellano replied.

“What about the Barbie laptop?”

“Sold out.”

Watching Castellano for a few hours, I couldn’t help but feel a new respect for that underappreciated hero, the Grinch. Even in a year when we’ve all learned firsthand that just being alive is a gift, the lesson of that children’s story – that Christmas can be wondrous even without excess – still eludes America.

It certainly eluded Ruth Ramos, who actually cried when Castellano informed her of the Nutcracker shortage.

“I have to get it for my 6-year-old,” she sobbed. “You have no idea how angry she’ll get. She’s very demanding.”

The Barbie department was the perfect place to study humanity stretched to the breaking point. You could see it in the furrowed brows as adults looked up at the wall of Barbie dolls, all the same, yet subtly different.

“I hate Barbie,” said one man standing at the sacred altar. “But you get your kids what they want because it keeps them happy. A happy child is a happy household.”

He would not give his name. He was anything but happy as he walked off with a “Fashion Designer” Barbie.

Nearby, a man was yelling into his cell phone the names of potential gifts. (Finally, a use for cell phones!)

“They only have the Fisher Price ‘Talk ‘n Travel Van,’ ” he worried. “Is that the one she wants?” He wanted to get his niece the proper accessory to her Fisher Price country home.

“It wasn’t this way when I was a kid,” said the man, Victor Medrano. “They’re not kids anymore – they’re consumers.”

But in a year when everyone from the president to the mayor has said it’s patriotic to spend the economy back into the black, it’s difficult to stop the inanity.

Which brings us to Ivonne Anderson, who is spending $500 trying to please her 5-year-old daughter.

“I guess I’m going a little crazy,” Anderson said, as she hunted the elusive Nutcracker, the hottest thing since they gave the big-breasted broad a boy-toy named Ken. “But you don’t even think about it.”